JP2001148385A - Semiconductor wafer and manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of defective adherence between a metallic wiring made of copper or copper alloy and an insulation film suppressing copper diffusion, and to provide a manufacturing method of a semiconductor device free from hillock generation. SOLUTION: The surface of a wafer and a copper wiring are treated against corrosion with a corrosion-proof treatment 25 after the copper surface is purified by spin cleaning 24. A corrosion-proof solution of BTA aqueous solution adding 1% BTA is sprayed onto the surface of the wafer at 1 liter/min for 10 sec while rotating the semiconductor wafer, and the copper film is treated against corrosion. Cu-BTA compound is produced as a corrosion-proof film on the surface of the copper wiring 17. Therefore, the surface is never oxidized even it is left in open air, and excellent adherence can be obtained in the interface of Cu/Si3N4 even when Si3N4 film formation is followed thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor wafer, and more particularly to a method for manufacturing a semiconductor wafer including a step of cleaning a semiconductor device having copper or a copper alloy exposed. And a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In recent years, copper or a copper alloy containing 80% or more of copper (hereinafter referred to as C
u) are being used. Wiring using Cu
Generally, it is produced by a damascene method. FIG. 7 shows steps of a conventional method for manufacturing a semiconductor device for producing a damascene Cu wiring. FIG. 8 shows a partial cross section of the semiconductor wafer in this manufacturing process.

[0003] As shown in FIG.
Alternatively, a silicon oxide film (hereinafter referred to as S
An insulating film 12 such as an iO ₂ film) is formed, and wiring is formed in a part of the insulating film. Ta, Ta inside the wiring groove
A barrier film 14 such as N is formed, and the seed Cu film 1 is formed.
5 is formed by a sputtering method or a CVD method, and Cu16 is attached by electrolytic plating.

The above-described semiconductor wafer 1 is loaded into a cleaning apparatus, and Cu-CMP step 20 shown in FIG.
, The upper Cu is removed, and a Cu wiring 17 is formed as shown in FIG.

[0005] Next, in a scrub cleaning step 22, particle contamination is removed by a brush scrub or the like, and subsequently, in a spin cleaning step 24, metal contamination is removed with a carboxylic acid-based (oxalic acid) cleaning solution. Next, spin rinse
In the drying step 26, the wafer is rinsed and dried, and is unloaded from the cleaning device.

Then, in a film forming step 28, the semiconductor wafer
A silicon nitride film (hereinafter referred to as Si_Three N_Four Note as membrane
To form a Cu diffusion suppression insulating film such as SiON.
To the film forming apparatus, and as shown in FIG.
For example, Si _Three N_Four The film 18 is formed
You. After that, the SiO_Two Is formed.

In the above manufacturing process, the semiconductor wafer is
After the post-MP cleaning and removal from the cleaning device, the Si
Until it is loaded into the vacuum chamber of ₃ N ₄ film forming apparatus, the semiconductor wafer is left in the atmosphere. Although this waiting time depends on the waiting time until the film is loaded into the film forming apparatus, it is assumed that the actual manufacturing site waits on a daily basis.

[0008]

In the above-mentioned conventional method for manufacturing a semiconductor device, the semiconductor wafer exposed to the air is exposed to C
When the u-diffusion suppressing insulating film is formed, there is a problem that the adhesion at the interface between the Cu surface and the Cu diffusion suppressing insulating film is deteriorated.

During the formation of the Cu diffusion suppressing insulating film or during a subsequent process, when a stress of the film is applied or heat treatment is performed, a hillock (hill) is formed on the surface of the Cu wiring.
lllock) sometimes occurred.

If there is a poor adhesion at the interface of the Cu / Cu diffusion suppressing insulating film as described above, the current stress generated when a current flows through the Cu wiring causes Cu to form a gap between the Cu wiring and the Cu diffusion suppressing insulating film. And a short circuit occurs between the wiring and an adjacent wiring, which causes a problem of lowering the reliability of the semiconductor device. Further, when hillocks are generated on the surface of the Cu wiring, the reliability of the semiconductor device is reduced.

The inventors of the present application have investigated the cause and found the following. That is, CMP
If the wafer is exposed to the air after the post-cleaning and before the formation of the Cu diffusion suppressing insulating film, the surface of the Cu wiring is oxidized and CuOx
(Hereinafter referred to as CuO), which is a cause of poor adhesion. Further, when CuO is unevenly formed on the surface of the Cu wiring, that is, in a case where a formed portion and a non-formed portion exist in a distributed manner, hillocks may be generated.

Therefore, the inventors of the present application have found that even if the semiconductor wafer is exposed to the atmosphere before the formation of the Cu diffusion suppressing insulating film, the Cu wiring surface is not oxidized, and thus CuO is formed on the Cu wiring surface. I came up with something that should not be done.

Accordingly, an object of the present invention is to provide a semiconductor wafer in which the surface of a Cu wiring is not oxidized even when exposed to the atmosphere.

Another object of the present invention is to provide a method for manufacturing such a semiconductor wafer.

Still another object of the present invention is to provide a method for manufacturing a semiconductor device which solves the problem of poor adhesion to a Cu diffusion preventing insulating film.

Still another object of the present invention is to provide a method of manufacturing a semiconductor device in which hillocks are prevented from occurring.

[0017]

According to the method of manufacturing a semiconductor wafer of the present invention, in a cleaning process after Cu-CMP for forming damascene Cu wiring, the semiconductor wafer is treated with an aqueous solution containing an anticorrosive agent. Thus, an anticorrosion film made of a compound of Cu and an anticorrosive is formed on the surface of the Cu wiring. The presence of this film can prevent oxidation of the Cu wiring surface. Therefore, even before the semiconductor wafer is exposed to the atmosphere, the Cu wiring surface is not oxidized before the next step of forming the Cu diffusion suppressing film, so that the formed Cu
The adhesion of the diffusion suppressing insulating film is improved. Further, since the CuO film is not formed, hillocks do not occur on the Cu wiring surface due to the heat treatment process.

In order to suppress the diffusion of Cu from the Cu wiring, the insulating film coated on the wiring is made of Si ₃ N ₄ , SiO 2
N, SiO ₂ and the like.

Benzotriazole (BTA) is known as a typical anticorrosive for Cu. A technique using BTA when forming wiring in a semiconductor device is disclosed in
594, "Method of forming wiring", and JP-A-11-405.
No. 26, “Wiring forming method and semiconductor device manufacturing method”
Has already been disclosed. In these techniques, BTA is brought into contact with the Cu surface at the same time as or immediately after CMP to enhance the anticorrosion effect.

The present invention differs from these prior arts in that C
In the cleaning process after the MP, the surface of the metal wiring is treated with an aqueous solution containing an anticorrosive agent.

Further, the present inventors have proposed, as an anticorrosive, a four-membered ring compound having two nitrogen atoms, a five- or six-membered heterocyclic ring compound having three nitrogen atoms, or a derivative thereof,
Alternatively, it was confirmed that an anticorrosive composed of a mixture of two or more of these was effective.

The three-nitrogen hetero five-membered ring compound is a triazole-based compound, and the three-nitrogen hetero six-membered ring compound is a triazine-based compound. Examples of the triazole-based compound include, in addition to the above-mentioned benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, dihydroxypropylbenzotriazole, and the like. Can be. Furthermore, derivatives of benzotriazole, for example, Irgamet series commercially available from Ciba Specialty Chemicals, specifically Irgamet 42 (2,2 '-[[(methyl-1H-benzotriazole-1) -Yl) methyl] imino] bis-ethanol) and the like are also suitably used.

It has been confirmed that the effect of adding these anticorrosives is 1 ppm or more. The maximum addition ratio of BTA and the like is preferably set to 5% in view of environmental problems and solubility.

As other anticorrosive agents, compounds having an aromatic benzene ring, such as gallic acid and tannic acid, which are oxidation inhibitors, can also be used. These addition rates are
It is preferable to set the content to 0.01 to 5% based on the same idea as the anticorrosive such as BTA.

The treatment with the aqueous solution (anticorrosion liquid) to which the anticorrosive agent is added as described above must be performed as a continuous sequence in a post-CMP cleaning apparatus. Because, for example,
The anticorrosion treatment is performed after the spin cleaning for removing metal contamination. If there is a discontinuity in time between the steps, CuO may be formed on the metal surface.

In order to avoid such a problem, at the time of spin cleaning for removing metal contamination, an anticorrosive solution may be mixed with the cleaning solution so that the cleaning and the anticorrosion treatment are performed simultaneously.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION

[0028]

First Embodiment FIG. 1 is a process chart showing a method of manufacturing a semiconductor device according to a first embodiment of the present invention. The difference from the conventional manufacturing method of FIG. 7 is that an anticorrosion treatment step 25 is added. Therefore, in FIG. 1, the same steps as those in FIG. 7 are denoted by the same reference numerals. In addition,
The semiconductor device manufactured in this embodiment is the same as that described with reference to FIG.

In the Cu-CMP step 20, Cu-CMP on the insulating film 12 formed on the semiconductor wafer 1 having the structure shown in FIG.
(Seed Cu 15, plating Cu 16) and the barrier film 14 are polished and removed by CMP to form a Cu wiring 17 (see FIG. 8B). It is known that an anticorrosive such as BTA is added to the CMP slurry to prevent the Cu surface from being oxidized.

After Cu-CMP, the surface of the semiconductor wafer becomes
Particles such as abrasive grains and polishing debris, metals, slurries, etc. adhere and are contaminated.

In the scrub cleaning step 22, first, the brush is moved while applying a cleaning liquid such as electrolytic ionic water or dissolved hydrogen water to the rotating brush to remove particle contamination.

Next, in a spin cleaning step 24, a cleaning liquid composed of a 0.03% aqueous solution of oxalic acid, which is a carboxylic acid, is sprayed for 10 seconds while rotating the semiconductor wafer.
Metal contamination, that is, CuO on the surface is removed and rinsed with pure water. The concentration of oxalic acid may be a 0.01 to 1% aqueous solution, and the time for spraying the aqueous solution may be 10 to 30 seconds. In addition to oxalic acid, an organic acid such as citric acid may be used.

Next, in the anticorrosion treatment step 25, the surface of the wafer is treated to prevent the Cu wiring 17 from being corroded. As the anticorrosion solution, a BTA aqueous solution to which 1% BTA was added was prepared, and while rotating the semiconductor wafer 1, the BTA aqueous solution was sprayed onto the wafer surface at a flow rate of 1 liter / min for 10 seconds to perform corrosion prevention of the Cu film. .

In the next spin rinsing / drying step 26, the substrate was rinsed with pure water for 15 seconds and then dried.

Further, the present inventors have proposed, as an anticorrosive, any one of a nitrogen four-membered heterocyclic compound, a nitrogen three-membered five- or six-membered ring compound, and a derivative thereof.
It was confirmed that an anticorrosive consisting of a seed or a mixture of two or more of these was effective.

The five-membered heterocyclic compound having three nitrogen atoms is a triazole compound, and the six-membered heterocyclic compound having three nitrogen atoms is a triazine compound. Examples of the triazole-based compound include, in addition to the above-mentioned benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, dihydroxypropylbenzotriazole, and the like. Can be. Furthermore, derivatives of benzotriazole, for example, Irgamet series commercially available from Ciba Specialty Chemicals, specifically Irgamet 42 (2,2 '-[[(methyl-1H-benzotriazole-1) -Yl) methyl] imino] bis-ethanol) and the like are also suitably used.

It was confirmed that the effect of adding these anticorrosives was 1 ppm% or more. The maximum addition ratio of BTA and the like is preferably set to 5% in view of environmental problems and solubility.

As other anticorrosive agents, compounds having an aromatic benzene ring, such as gallic acid and tannic acid, which are oxidation inhibitors, can also be used. These addition rates are
It is preferable to set the content to 0.01 to 5% based on the same idea as the anticorrosive such as BTA.

After the semiconductor wafer obtained as described above is allowed to stand in the air for several hours to several days, in a film forming step 28, a Si ₃ N ₄ film 18 is formed at 400 ° C. by a CVD method for 10 to 10 days. Treated for 15 seconds, Si ₃ N ₄ film 1 with a thickness of 50 nm
8 was formed, and a plasma oxide film was formed thereon at 400 ° C. for 7 minutes.
By treating for 0 seconds, an interlayer film 19 was formed to a thickness of 1.1 μm (FIG. 8
(C)).

As a comparative example, a semiconductor wafer which was not subjected to the anti-corrosion treatment in the above-mentioned process was manufactured, and the same process was performed for several hours.
After being left in the air for several days, a Si ₃ N ₄ film was formed.

In the manufacturing process according to the present embodiment and the manufacturing process for the comparative example, TOF-SIMS (Time of Flight), which is a kind of chemical state analyzer, is used.
t-Secondary Ion Mass Spec
(troscopy), the surface was observed, and the generation state of CuO as an oxide film and Cu-BTA as an anticorrosion film was examined. The TOF-SIMS irradiates the surface of a sample (semiconductor wafer 1) with primary ions in a pulsed manner to generate secondary ions from the sample surface, and counts the mass and the number of the secondary ions to obtain a sample. This device analyzes the chemical state of the sample surface without breaking the chemical bonds on the surface.

With respect to Cu-BTA and CuO, the wafer after the spin rinsing / drying step 26 and before the Si ₃ N ₄ film forming step 28 was examined. The result is shown in FIG.
4 to FIG. FIGS. 2A and 2B each show Cu
O, FIG. 3 shows TOF-SIMS measurement results for organic and ionic substances present in the atmosphere, and FIG. 4 shows the results of TOF-SIMS measurement for Cu-BTA. In FIGS. 2A and 4, the vertical axis represents intensity (the ion count number is expressed in arbitrary units (AU)), and the horizontal axis represents the mass number.

FIG. 2A shows a spin rinse / dry (FIG. 1)
After the semiconductor wafer 1 obtained in step 26) was left in the atmosphere for 7 days, the CuO strength was measured by TOF-SIMS. As can be seen from the measurement results of FIG.
It can be seen that the formation of CuO is suppressed in the semiconductor wafer subjected to the anticorrosion treatment (BTA treatment) according to the present invention. Further, as shown in the comparative example (without BTA processing), the BT
It can be seen that even the semiconductor wafer 1 CMPed with the slurry containing A has little anticorrosion effect.

FIG. 2B shows the relationship between the number of days that the semiconductor wafer 1 is left in the air after spin rinsing and drying (step 26 in FIG. 1) and the CuO strength. As shown in FIG. 2B, the comparative example (without BTA processing)
It can be seen that the CuO strength increases as the number of days of standing increases, and that the oxidation of Cu easily proceeds. On the other hand, in the example (with BTA treatment), the increase in the CuO strength is gradual even when the number of days of standing is increased, and it can be seen that the oxidation of Cu is difficult to proceed.

FIG. 3 shows the relationship between the number of days that the semiconductor wafer 1 is left in the air after spin rinsing and drying (step 26 in FIG. 1) and the strength of organic substances. Here, the organic matter is a substance floating in the air in the clean room, and is presumed to be generated from a paint on a wall or a manufacturing apparatus, a lubricant attached to a movable portion of the manufacturing apparatus, or the like.

As shown in the comparative example (without BTA treatment) in FIG. 3, even in the semiconductor wafer 1 which has been subjected to CMP with the slurry containing BTA, the organic matter easily adheres, and as the number of days of standing increases, the organic matter adheres. It can be seen that the amount increases significantly.

On the other hand, the embodiment (with BTA processing)
It can be seen that the increase in the strength of the organic substance is gradual even when the number of days of standing increases, and that the adhesion of organic substances and ionic contaminants harmful to the manufacture of the semiconductor wafer 1 can be significantly suppressed.

FIG. 4 shows the result of measuring the Cu-BTA intensity by TOF-SIMS after leaving the semiconductor wafer 1 spin-rinsed and dried (step 26 in FIG. 1) in the air for 7 days.

As is clear from the measurement results of FIG. 4, the semiconductor wafer 1 subjected to the anticorrosion treatment has a C as an anticorrosion film.
The presence of u-BTA was confirmed. In addition, a comparative example (BTA
As shown in (No treatment), even if the semiconductor wafer 1 is CMP-processed with a slurry containing BTA, the Cu-BT
It turns out that the residual amount of A is small. Furthermore, when combined with the results of FIG. 2, when CuO is formed on the Cu surface, C
It turns out that u-BTA is hard to be formed.

Next, the semiconductor wafer subjected to the anti-corrosion treatment according to the present embodiment and the above-described semiconductor wafer manufactured as a comparative example,
After standing for three days, after standing for three days, and after standing for seven days, a film of Si ₃ N ₄ was subjected to an adhesion test at the Cu / Si ₃ N ₄ interface. In this test, an adhesive tape was stuck on a Si ₃ N ₄ film in which lines were formed in a grid pattern at a pitch of 1 mm, and this was peeled off, and the cells of the Si ₃ N ₄ film peeled from the wafer in 100 cells Was counted.

Table 1 shows the test results. As is clear from the above, in any of the samples without the BTA treatment, peeling of the Si ₃ N ₄ film occurred, and after performing the spin rinsing / drying step 26, the Si ₃ N ₄ film was left in the air to stand.
₃ N ₄ film The longer the period until the formation of the,
It can be seen that the number of peeling increases and the adhesion at the Cu / Si ₃ N ₄ interface is deteriorated. On the other hand, those located BTA treatment, be those obtained by forming a Si ₃ N ₄ Makujo after standing 7 days, Si ₃ N ₄ film peeling not, Cu
It can be seen that the adhesion of the / Si ₃ N ₄ film is good.

[0052]

[Table 1]

Table 2 shows the relationship between the BTA concentration and the number of peeled Si ₃ N ₄ films. The method of the adhesion test is as follows.
After immersing the semiconductor wafer 1 in the aqueous solution A for 10 seconds, the number of cells where the Si ₃ N ₄ film adhered to the adhesive tape was counted as described above. As shown in Table 2, the BTA concentration was 1 p.
At pm to 1%, there was no peeling of the Si ₃ N ₄ film and C
It can be seen that the adhesion between u and the Si ₃ N ₄ film is good. The same effect can be obtained when the BTA concentration is 1% or more, but BTA does not dissolve in water at 2 to 5% or more.

[0054]

[Table 2]

Table 3 shows that the spin cleaning (oxalic acid treatment) 24
Process of anti-corrosion treatment (BTA treatment) 25 and Si ₃
An example of testing the relationship between the number of peeling of N ₄ film. The semiconductor wafer 1 used in the test was subjected to spin rinsing / drying 26, allowed to stand in the air for 7 days, and then formed with a Si ₃ N ₄ film.

[0056]

[Table 3]

From the test results shown in Table 3, the semiconductor wafer 1 on which metal contamination has not been removed (oxalic acid treatment) has been
The treatment cannot improve the adhesion of the Si ₃ N ₄ film. Further, even if the semiconductor wafer 1 has been subjected to metal contamination removal, the adhesion of the Si ₃ N ₄ film cannot be improved unless the BTA treatment is performed. Thus, it can be seen that the anti-corrosion treatment 25 has no effect unless it is performed after the Cu surface is cleaned, that is, after removing CuO and metal contamination.

As another anticorrosive, a 1% aqueous solution of gallic acid having an oxidation inhibiting effect was used in place of the BTA aqueous solution to prepare a semiconductor wafer, and the wafer was exposed to the air for 1 day, 3 days, and 3 days.
The sheet resistance of the Cu wiring was measured for those left for 7 days. For comparison, 0.1% BTA aqueous solution, 1% B
The rate of change of the sheet resistance was measured for those subjected to the anticorrosion treatment with the TA aqueous solution and those not subjected to the anticorrosion treatment.

FIG. 5 shows the measurement results. As for the unprocessed semiconductor wafer, the change in the sheet resistance of the Cu wiring increases as the time in which the wafer is left in the air increases.
The change in sheet resistance of the semiconductor wafers subjected to the anticorrosion treatment with the TA aqueous solution and the gallic acid aqueous solution was small.
From this, it is understood that both the BTA aqueous solution and the gallic acid aqueous solution prevent corrosion of the Cu wiring and are effective in reducing the sheet resistance.

In the case of a semiconductor device which has been subjected to anticorrosion treatment with a BTA aqueous solution and a gallic acid aqueous solution, the formation of an Si ₃ N ₄ film or the formation of an interlayer film such as a silicon oxide film is reduced by 40%.
Even after a heat treatment at 0 ° C. for 5 minutes, generation of hillocks was not confirmed.

[0061]

Second Embodiment FIG. 6 is a process chart showing a method for manufacturing a semiconductor device according to a second embodiment of the present invention. The difference from the first embodiment is that the anticorrosion treatment step 25 in FIG. 1 is omitted by adding BTA to the oxalic acid aqueous solution during spin cleaning for removing metal contamination. In FIG. 6, reference numeral 30 denotes a spin cleaning (metal contamination prevention process + corrosion prevention process). In other steps, the same steps as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

In step 30, for example, an aqueous solution containing 0.03% oxalic acid and 0.5% BTA is sprayed while rotating the semiconductor wafer.
And rinsed. Here, oxalic acid is C
It has a function of removing metal contaminants adhering to the semiconductor wafer 1 by MP and a CuO film on the surface. In addition, BTA has an anticorrosion function similarly to the first embodiment, and in addition to BTA, the present inventors furthermore, as an anticorrosion agent, a two-nitrogen four-membered ring compound or a three-nitrogen complex compound. It was confirmed that an anticorrosive composed of one of a five-membered or six-membered ring compound or a derivative thereof, or a mixture of two or more thereof was effective.

One example of a heterocyclic four-membered ring compound is indazole.

The five-membered heterocyclic compound having three nitrogen atoms is a triazole compound, and the six-membered heterocyclic compound having three nitrogen atoms is a triazine compound. Examples of the triazole-based compound include, in addition to the above-mentioned benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, dihydroxypropylbenzotriazole, and the like. Can be. Furthermore, derivatives of benzotriazole, for example, Irgamet series commercially available from Ciba Specialty Chemicals, specifically Irgamet 42 (2,2 '-[[(methyl-1H-benzotriazole-1) -Yl) methyl] imino] bis-ethanol) and the like are also suitably used.

It was confirmed that the effect was exhibited at an addition rate of these anticorrosives of 1 ppm% or more. The maximum addition ratio of BTA and the like is preferably set to 5% in view of environmental problems and solubility.

As other anticorrosive agents, compounds having an aromatic benzene ring, such as gallic acid and tannic acid, which are oxidation inhibitors, can also be used. These addition rates are
It is preferable to set the content to 0.01 to 5% based on the same idea as the anticorrosive such as BTA.

In this embodiment, it was confirmed that an anticorrosion film was formed on the surface of the Cu wiring, as in the first embodiment. Further, according to the present embodiment, it is possible to improve the adhesion of the Cu / Cu diffusion suppression insulating film without increasing the number of steps.

[0068]

As described above, according to the present invention, C
In a semiconductor device in which a Cu diffusion inhibiting insulating film is formed on the surface of a damascene metal interconnect made of u or Cu alloy, the adhesion between the metal interconnect and the Cu diffusion inhibiting insulating film can be improved, and Since no hillocks are generated on the wiring surface, a highly reliable semiconductor device can be provided.

The anticorrosion treatment according to the present invention uses a low dielectric constant (Low-K) film as an interlayer insulating film.
This is important when a Cu wiring is formed in the film. In general,
The Low-K film easily contains moisture as compared with the SiO ₂ film, and in the conventional method, the moisture affects the Cu wiring, and the Cu wiring is easily oxidized. However, according to the method of the present invention, since the adhesion between the Cu wiring and the Si ₃ N ₄ film is high, it is difficult for moisture to enter. Further, since the Cu wiring surface is subjected to anticorrosion treatment, even if moisture enters, Oxidation can be suppressed.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a graph showing the results of TOF-SIMS measurement of CuO.

FIG. 3 is a graph showing a result of TOF-SIMS measurement for an organic substance.

FIG. 4 is a graph showing TOF-SIMS measurement results for Cu-BTA.

FIG. 5 is a diagram showing measurement results of sheet resistance.

FIG. 6 is a process chart showing a method for manufacturing a semiconductor device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing steps of a conventional method of manufacturing a semiconductor device for producing a damascene Cu wiring.

FIG. 8 is a partial cross section of a semiconductor wafer in a manufacturing process.

[Explanation of symbols]

Reference Signs List 10 semiconductor substrate 12 insulating film 14 barrier film 15 Cu film 16 plated Cu 17 Cu wiring 18 Si ₃ N ₄ film 19 interlayer film 20 Cu-CMP process 22 scrub cleaning process 24 spin cleaning process 26 spin rinsing / drying process 28 film forming process 29 Interlayer film formation process 30 (Spin cleaning + anticorrosion treatment) process

Continued on the front page F term (reference) 5F033 HH11 HH12 HH21 HH32 MM01 MM12 MM13 NN06 NN07 PP06 PP15 PP27 PP33 QQ37 QQ48 QQ91 RR04 RR06 RR08 SS11 SS15 XX16 XX18 XX20

Claims (27)

[Claims] 1. A method for manufacturing a semiconductor device, comprising: performing a corrosion prevention treatment with an aqueous solution containing a corrosion inhibitor before forming a copper diffusion suppressing insulating film on a surface of a semiconductor substrate where copper or a copper alloy is exposed. 2. The manufacturing method of a semiconductor device according to claim 1, wherein said semiconductor substrate having copper or copper alloy exposed thereon is a semiconductor substrate on which metal wiring made of copper or copper alloy is formed by a damascene method. Method. 3. The copper or copper alloy is subjected to chemical mechanical polishing (CM).
3. The method of manufacturing a semiconductor device according to claim 1, wherein the anticorrosion treatment is performed during a cleaning step after P). 4. The method according to claim 1, wherein the anticorrosion treatment is performed immediately after the treatment with a cleaning solution for removing metal contamination.
4. The method for manufacturing a semiconductor device according to any one of 2 and 3. 5. The semiconductor device according to claim 1, wherein the anticorrosion treatment is performed simultaneously with the cleaning by adding an anticorrosive to the cleaning liquid during cleaning for removing metal contamination. Manufacturing method. 6. The method according to claim 4, wherein the cleaning liquid is a carboxylic acid cleaning liquid. 7. The anticorrosion agent is a heterocyclic four-membered compound having two nitrogen atoms, a five- or six-membered heterocyclic compound having three nitrogen atoms, or a derivative thereof, or two or more of these compounds. A mixture of:
7. The method for manufacturing a semiconductor device according to any one of 6. 8. The method according to claim 7, wherein said four-membered heterocyclic compound is indazole or a derivative thereof. 9. The five-membered heterocyclic compound is benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, or dihydroxypropylbenzotriazole. 8. The method for manufacturing a semiconductor device according to claim 7, wherein 10. The addition rate of said anticorrosive is 1 ppm to 5%.
The method of manufacturing a semiconductor device according to claim 1, wherein: 11. The anticorrosive according to claim 1, wherein the anticorrosive comprises a compound having an aromatic benzene ring, a derivative thereof, or a mixture of two or more of them. 13. The method for manufacturing a semiconductor device according to item 5. 12. The method according to claim 11, wherein the compound having an aromatic benzene ring is gallic acid or tannic acid. 13. The method according to claim 1, wherein an addition ratio of said gallic acid or tannic acid is 0.01 to 5%.
3. The method for manufacturing a semiconductor device according to item 2. 14. The method of manufacturing a semiconductor device according to claim 1, wherein said copper diffusion suppressing insulating film is made of Si ₃ N ₄ or SiON. 15. A method for manufacturing a semiconductor wafer having metal wiring made of copper or a copper alloy by a damascene method, comprising: a step of forming a metal wiring by performing a CMP process on a metal; and a step of cleaning after the CMP processing. And a step of subjecting the surface of the metal wiring to anticorrosion treatment with an aqueous solution to which an anticorrosive agent has been added. 16. The method according to claim 15, wherein the anticorrosion treatment is performed immediately after cleaning for removing metal contamination. 17. The method of manufacturing a semiconductor wafer according to claim 16, wherein the anticorrosion treatment is performed simultaneously with the cleaning by adding an anticorrosive to the cleaning liquid during cleaning for removing metal contamination. 18. The method according to claim 17, wherein the cleaning liquid is a carboxylic acid-based cleaning liquid. 19. The anticorrosive may be a four-membered ring compound having two nitrogen atoms, a five-membered or six-membered ring compound having three nitrogen atoms, or a derivative thereof, or a combination of two or more thereof. 16. A mixture comprising a mixture.
19. The method for manufacturing a semiconductor wafer according to any one of items 18 to 18. 20. The method according to claim 19, wherein the four-membered ring compound is indazole or a derivative thereof. 21. The five-membered heterocyclic compound is benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, or dihydroxypropylbenzotriazole. 20. The method for manufacturing a semiconductor wafer according to claim 19, wherein 22. The addition rate of the anticorrosive is 1 ppm to 5%.
22. The method of manufacturing a semiconductor wafer according to claim 15, wherein: 23. The anticorrosive according to claim 15, wherein the anticorrosive comprises a compound having an aromatic benzene ring, a derivative thereof, or a mixture of two or more of them. 3. The method for manufacturing a semiconductor wafer according to 1. 24. The method according to claim 23, wherein the compound having an aromatic benzene ring is gallic acid or tannic acid. 25. The method according to claim 2, wherein the addition ratio of said gallic acid or tannic acid is 0.01 to 5%.
5. The method for manufacturing a semiconductor wafer according to 4. 26. A semiconductor wafer manufactured by the method according to claim 15, wherein an anticorrosion film made of a compound of copper and the anticorrosive is formed on a surface of the metal wiring. A semiconductor wafer. 27. The semiconductor wafer according to claim 26, wherein said compound is copper-BTA which is a compound of copper and benzotriazole (BTA).